Adding forceformat option: format invalid output just like jsonlint.com

When using jsonlint.com, even invalid JSON is pretty printed. It seemed
like a good option to have in the cli version as well. This is simply
inserting the char-by-char formatter from
https://github.com/umbrae/jsonlintdotcom and adding an option to cli.js.

lib/cli.js

@@ -4,6 +4,7 @@ var fs = require("fs");
 var path = require("path");
 var parser = require("./jsonlint").parser;
 var JSV = require("JSV").JSV;
+var formatter = require("./formatter.js").formatter;
 
 var options = require("nomnom")
   .script("jsonlint")
@@ -50,10 +51,16 @@ var options = require("nomnom")
         help: 'which specification of JSON Schema the validation file uses'
     },
     quiet: {
-        flag:  true,key: "value",
+        flag:  true,
+        key: "value",
         string: '-q, --quiet',
         "default": false,
-        help : 'do not print the parsed json to STDOUT'
+        help: 'do not print the parsed json to STDOUT'
+    },
+    forcePrettyPrint: {
+        flag:  true,
+        string: '-p, --pretty-print',
+        help: 'force pretty printing even if invalid'
     }
   }).parse();
 
@@ -66,10 +73,13 @@ if (options.compact) {
 }
 
 function parse (source) {
+  var parsed,
+      formatted;
+
   try {
-    var parsed = options.sort ?
-                  sortObject(parser.parse(source)) :
-                  parser.parse(source);
+    parsed = options.sort ?
+      sortObject(parser.parse(source)) :
+      parser.parse(source);
 
     if (options.validate) {
       var env = JSV.createEnvironment(options.env);
@@ -82,10 +92,31 @@ function parse (source) {
 
     return JSON.stringify(parsed,null,options.indent);
   } catch (e) {
-    if (! options.compact) {
+    if ( options.forcePrettyPrint ) {
+      /* From https://github.com/umbrae/jsonlintdotcom:
+       * If we failed to validate, run our manual formatter and then re-validate so that we
+       * can get a better line number. On a successful validate, we don't want to run our
+       * manual formatter because the automatic one is faster and probably more reliable.
+       */
+
+      try {
+        formatted = formatter.formatJson(source, options.indent);
+        // Re-parse so exception output gets better line numbers
+        parsed = parser.parse(formatted);
+      } catch (e) {
+        if (! options.compact) {
+          console.error(e);
+        }
+        return formatted;
+        process.exit(1);
+      }
+    } else {
+      if (! options.compact) {
         console.error(e);
+      }
+
+      process.exit(1);
     }
-    process.exit(1);
   }
 }
 

lib/formatter.js

@@ -0,0 +1,92 @@
+#!/usr/bin/env node
+
+/**
+ * Manual formatter taken straight from https://github.com/umbrae/jsonlintdotcom
+**/
+
+/*jslint white: true, devel: true, onevar: true, browser: true, undef: true, nomen: true, regexp: true, plusplus: false, bitwise: true, newcap: true, maxerr: 50, indent: 4 */
+
+/**
+ * jsl.format - Provide json reformatting in a character-by-character approach, so that even invalid JSON may be reformatted (to the best of its ability).
+ *
+**/
+var formatter = (function () {
+
+    function repeat(s, count) {
+        return new Array(count + 1).join(s);
+    }
+
+    function formatJson(json, indentChars) {
+        var i           = 0,
+            il          = 0,
+            tab         = (typeof indentChars !== "undefined") ? indentChars : "    ",
+            newJson     = "",
+            indentLevel = 0,
+            inString    = false,
+            currentChar = null;
+
+        for (i = 0, il = json.length; i < il; i += 1) { 
+            currentChar = json.charAt(i);
+
+            switch (currentChar) {
+            case '{': 
+            case '[': 
+                if (!inString) { 
+                    newJson += currentChar + "\n" + repeat(tab, indentLevel + 1);
+                    indentLevel += 1; 
+                } else { 
+                    newJson += currentChar; 
+                }
+                break; 
+            case '}': 
+            case ']': 
+                if (!inString) { 
+                    indentLevel -= 1; 
+                    newJson += "\n" + repeat(tab, indentLevel) + currentChar; 
+                } else { 
+                    newJson += currentChar; 
+                } 
+                break; 
+            case ',': 
+                if (!inString) { 
+                    newJson += ",\n" + repeat(tab, indentLevel); 
+                } else { 
+                    newJson += currentChar; 
+                } 
+                break; 
+            case ':': 
+                if (!inString) { 
+                    newJson += ": "; 
+                } else { 
+                    newJson += currentChar; 
+                } 
+                break; 
+            case ' ':
+            case "\n":
+            case "\t":
+                if (inString) {
+                    newJson += currentChar;
+                }
+                break;
+            case '"': 
+                if (i > 0 && json.charAt(i - 1) !== '\\') {
+                    inString = !inString; 
+                }
+                newJson += currentChar; 
+                break;
+            default: 
+                newJson += currentChar; 
+                break;                    
+            } 
+        } 
+
+        return newJson; 
+    }
+
+    return { "formatJson": formatJson };
+
+}());
+
+if (typeof require !== 'undefined' && typeof exports !== 'undefined') {
+  exports.formatter = formatter;
+}